This invention relates to a banding system and to the clip and band which are used in connection with the banding system.
Banding systems are widely used in many industries for a variety of purposes. For example, they are used for baling and palletizing materials in the agricultural and packaging fields. The are also used for banding together electrical conductors and to clamp flexible duct to the metal collars of takeoffs and boots in heating, ventiliating and air conditioning systems.
In the heating, ventilating and air conditioning industry, hereinafter referred to as the HVAC industry, flexible duct has largely replaced round metal pipe and fiberglass wrap in air distribution systems. Metal takeoffs are installed in the extended plenum or square trunk duct, and flexible duct is run from the trunk to the boots on the registers, grills or difusers. The flexible duct is telescopically placed over the metal collars of the takeoffs and boots and circumferential clamps are applied to the ducts in position. A "clamp" in this respect is an integral body of injection molded plastic provided with a self-locking head at one end of a band. The band is positioned circurferentially around the duct, inserted through the locking head, and drawn tightly by a tensioning tool. When using such clamps, there is an unavoidable waste of band material unless, as is seldom the case, the contractor is able to maintain an inventory of clamps which have a wide variety of band lengths. For small diameter ducts, a substantial amount of the band material is cut from the clamp and wasted, while with larger ducts it is sometimes necessary to fasten two or more of the clamps together to achieve the circumference of the duct. The present invention utilizes a band of indeterminate length, i.e. a band which can be cut approximately to the required length without excessive wasting. The band can be tightened by an inexpensive tool, and the contractor is not required to maintain an inventory of devices of different band lengths.
Although not used significantly in the HVAC industry, there have been a number of banding systems which utilize indeterminate length band. Perhaps the best know of these are the strapping systems which use hand tightened buckles of metal or plastic, or those which have tightening tools and apply either metal clips or form a heat seal between the opposite end portions of the band. The hand tightened devices are not practical for HVAC purposes because sufficient tension cannot be applied to the circumferential band. As to the systems which use heat seal principles or metal clips in connection with the tightening tool, it has been found that the tools are too expensive to justify their usage in lieu of the clamping systems described in the previous paragraph. Self-locking buckles or clips for indeterminant length band were sold a number of years ago by Weckesser Company, Inc., Chicago, Ill., and are presently being sold by W. H. Brady Company, Milwaukee, Wisc. A bidirectional clip with toothed locking tangs is the subject of Valestin U.S. Pat. No. 4,377,887. However, the present invention presents a number of advantages which are not realized by the Weckesser and Valestin systems. One disadvantage of the Weckesser and Valestin systems is that they include bands which are provided with perforations which inherently weaken the band and are incapable of being spaced closely to each other in order to provide the relatively fine increments of adjustment achieved by the present invention. Other advantages of the present invention over Weckesser and Valestin are described elsewhere in this specification.
An important object of the invention is to provide a bidirectional one piece locking clip which can be manufactured inexpensively and can be used in connection with inexpensive indeterminant length band material. Another object is to provide an improved band which has a novel configuration and is preferably formed of fiberglass reinforced plastic which is extruded and embossed. Another object is to provide a clip for a banding system wherein the clip may conveniently be disengaged to release the band when desired. A further object is to provide a clip of the type described with a structure which permits an end of the band to protrude from the clip for tightening purposes without being obstructed by the clip and components which engage the opposite end of the band. Still another object is to provide a clip for a banding system in which a tool face is conveniently positioned between the two band engaging means for convenience of manufacture and usage. Still another object is to provide a banding system of the type described wherein the clip has a hinge formed therein so that the clip will conform to the shape of a duct or other object encircled by the looped band. Other objects and advantages will be recognizable by those skilled in the art from a study of the following drawings and descriptions.